Calculator
Ovulation calculator
Ovulation often lands about 14 days before the next period. Enter the first day of the last period and the usual cycle length. This does not confirm ovulation.
How the count works
The estimate is the cycle length minus 14 days after the first day of the last period. The fertile window shown here is that day plus the five days before it.
Irregular cycles, recent hormonal birth control, and breastfeeding can move ovulation. A home kit or a clinician can check what a calendar cannot.
ToddlerGuide is a handbook for ages 12 to 36 months. This calculator is here because the old address still gets requested.
Questions
When does this count place ovulation?
About 14 days before the next period. For the cycle length you enter, that is cycle length minus 14 days after the first day of the last period.
What is the fertile window here?
The estimated ovulation day and the five days before it. Sperm can survive several days. The egg does not. This page does not confirm that ovulation happened.
Can this tell me I am pregnant?
No. A late period has many causes. A pregnancy test and a clinician are how that question gets answered.
Source
- American College of Obstetricians and Gynecologists. Fertility awareness-based methods of family planning. acog.org
Related: Pregnancy due date calculator